This invention relates to power and free conveyor systems and particularly to an improved storage track section on which a plurality of multi-trolley carriers can be stored in accumulated relation in a minimum area for a given number of carriers.
A power and free conveyor includes a power track which supports power trolleys connected to an endless driven chain equipped with longitudinally spaced pushers, and a carrier track normally arranged in vertically spaced relation with the power track, a plurality of carriers being mounted on the carrier track. Each of these carriers, for purposes of the present invention, comprises a leading driving trolley, a first load carrying trolley connected to the driving trolley by a tow bar, and a second load carrying trolley connected to the first load carrying trolley by suitable load carrying structure. The driving trolley is provided with a driving dog which is engageable by one of the pushers and which is disengageable from the pusher by operating mechanism responsive to contact between the driving trolley and the rear trolley of a preceding, stopped carrier. Carriers of the foregoing type are shown in U.S. Pat. Nos. 4,408,540 and 4,616,570 to which reference is made.
U.S. Pat. No. 4,408,540, FIG. 1, illustrates a power and free conveyor system having portions in which the first and second load carrying trolleys of the carriers travel on a pair of parallel tracks so that the load carrying structure connecting these trolleys is placed in an oblique relation to the tracks, thus reducing the longitudinal spacing between successive carriers. In other power and free conveyor systems, the longitudinal spacing between successive carriers has been further reduced by providing three parallel tracks, one for each of the three trolleys of the carrier, the three tracks being arranged so that the entire carrier structure in substantially longitudinally aligned relation, extends obliquely to the three tracks. This three-track arrangement requires considerable space, since the overall transverse dimension of the conveyor must be increased.